U.S. patent application number 12/444788 was filed with the patent office on 2010-02-25 for disposable assembly for separating blood or scrubbing a blood component.
Invention is credited to Jean-Denis Rochat.
Application Number | 20100048373 12/444788 |
Document ID | / |
Family ID | 37807743 |
Filed Date | 2010-02-25 |
United States Patent
Application |
20100048373 |
Kind Code |
A1 |
Rochat; Jean-Denis |
February 25, 2010 |
DISPOSABLE ASSEMBLY FOR SEPARATING BLOOD OR SCRUBBING A BLOOD
COMPONENT
Abstract
The invention relates to a centrifugation enclosure (1) made of
rigid plastic that comprises a member (1b) adapted to engage with
the driving organ of a centrifugation machine (M) and a
communication member (5) between the enclosure (1) and the outside,
made of rigid plastic and comprising an first duct (5a) extending
therethrough for supplying said enclosure (1) as well as two ducts
(5b, 5c) extending therethrough for discharging the separated
components. A holder (3) made of rigid plastic and having a network
of channels (4a, 4b, 4c) formed therein connects the ducts (5a, 5b,
5c), respectively, to supply (P1) and reception (P2, P3) tanks,
with side sealing members (6) of said channel network (4a, 4b, 4c).
The ends of the ducts (5a, 5b, 5c) are adjacent to the respective
ends of the channels (4a, 4b, 4c), and the ends of the ducts (5a,
5b, 5c) have surfaces mating with the end surfaces of the
respective channels (4a, 4b, 4c), said mating surfaces being
connected to one another.
Inventors: |
Rochat; Jean-Denis;
(Genolier, CH) |
Correspondence
Address: |
WESTERMAN, HATTORI, DANIELS & ADRIAN, LLP
1250 CONNECTICUT AVENUE, NW, SUITE 700
WASHINGTON
DC
20036
US
|
Family ID: |
37807743 |
Appl. No.: |
12/444788 |
Filed: |
October 4, 2007 |
PCT Filed: |
October 4, 2007 |
PCT NO: |
PCT/CH2007/000491 |
371 Date: |
April 8, 2009 |
Current U.S.
Class: |
494/41 |
Current CPC
Class: |
B04B 5/0442 20130101;
A61M 1/3696 20140204; A61M 1/3616 20140204; A61M 1/3692 20140204;
A61M 1/3693 20130101; B04B 11/082 20130101; A61M 2205/12 20130101;
B04B 11/02 20130101 |
Class at
Publication: |
494/41 |
International
Class: |
B04B 7/12 20060101
B04B007/12; B04B 7/02 20060101 B04B007/02 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 10, 2006 |
EP |
06405432.3 |
Claims
1. A disposable assembly for separating blood or the washing of a
blood component by centrifugation, comprising a circular centrifuge
chamber made of a rigid plastic, comprising, at an end lying on its
axis of rotation, an element shaped in order to mesh with a drive
member of a centrifuge machine and, at an opposite end, a member
for interaction of said chamber with the outside made of a rigid
plastic, connected to said centrifuge chamber by a rotary joint and
passed through by a tube to supply this chamber and by at least one
outlet tube for draining at least one of the separate constituents,
a support made of a rigid plastic in which a network of channels is
formed in order to connect said tubes respectively to a supply
reservoir for the blood to be separated and to at least one
reception reservoir for a separated constituent, elements for
laterally closing this network of channels in a sealed manner and
means for circulating the fluids through this network of channels
from the supply reservoir to the reception reservoirs, wherein the
ends of said tubes passing through said member causing said chamber
to interact with the outside, concentric with said axis of
rotation, are adjacent to the respective ends of said channels, in
that the ends of said tubes have surfaces complementary to the
surfaces of the ends of said respective channels, and in that these
complementary surfaces are fixed to each other by joints in a
sealed manner so that said support and said member for causing said
chamber to interact with the outside form a rigid assembly.
2. The assembly as claimed in claim 1, in which the fixings between
the surfaces of the respective ends of said tubes and said channels
are non-removable fixings.
3. The assembly as claimed in claim 1, in which said support is
formed in a single piece with a case.
4. The assembly as claimed in claim 3, having an opening for at
least partly receiving the centrifuge chamber, the part of this
case opposite that which is adjacent to said support having a
second opening to allow the passage of said element shaped to mesh
with drive means (11a) of the centrifuge machine.
5. The assembly as claimed in claim 1, in which said support is a
planar support.
6. The assembly as claimed in claim 5, in which said planar support
is inclined relative to the axis of rotation of said centrifuge
chamber.
7. The assembly as claimed in claim 5, in which said planar support
is perpendicular to the axis of rotation of said centrifuge
chamber.
8. The assembly as claimed in claim 2, in which said support is
formed in a single piece with a case.
9. The assembly as claimed in claim 8, having an opening for at
least partly receiving the centrifuge chamber, the part of this
case opposite that which is adjacent to said support having a
second opening to allow the passage of said element shaped to mesh
with drive means of the centrifuge machine.
10. The assembly as claimed in claim 2, in which said support is a
planar support.
11. The assembly as claimed in claim 3, in which said support is a
planar support.
12. The assembly as claimed in claim 4, in which said support is a
planar support.
13. The assembly as claimed in claim 8, in which said support is a
planar support.
14. The assembly as claimed in claim 9, in which said support is a
planar support.
15. The assembly as claimed in claim 10, in which said planar
support is inclined relative to the axis of rotation of said
centrifuge chamber.
16. The assembly as claimed in claim 11, in which said planar
support is inclined relative to the axis of rotation of said
centrifuge chamber.
17. The assembly as claimed in claim 12, in which said planar
support is inclined relative to the axis of rotation of said
centrifuge chamber.
18. The assembly as claimed in claim 10, in which said planar
support is perpendicular to the axis of rotation of said centrifuge
chamber.
19. The assembly as claimed in claim 11, in which said planar
support is perpendicular to the axis of rotation of said centrifuge
chamber.
20. The assembly as claimed in claim 12, in which said planar
support is perpendicular to the axis of rotation of said centrifuge
chamber.
Description
[0001] The present invention relates to a disposable assembly for
separating blood or the washing of a blood component by
centrifugation, comprising a circular centrifuge chamber made of a
rigid plastic, comprising, at an end lying on its axis of rotation,
an element shaped in order to mesh with a drive member of a
centrifuge machine and, at an opposite end, a member for
interaction of said chamber with the outside made of a rigid
plastic, connected to said centrifuge chamber by a rotary joint and
passed through by a tube to supply this chamber and by at least one
outlet tube for draining one of the separate constituents, a
support made of a rigid plastic in which a network of channels is
formed in order to connect said tubes respectively to a supply
reservoir for the blood to be separated and to respective reception
reservoirs for the separated constituents, elements for laterally
closing this network of channels in a sealed manner and means for
circulating the fluids through this network of channels from the
supply reservoir to the reception reservoirs.
[0002] The single-use centrifugation assemblies used to separate
blood components from whole blood comprise two main parts: a
movable part corresponding to the centrifuge chamber and a fixed
part comprising storage pouches for blood components, flexible
tubing, and all the parts intended to be connected to the machine
controlling the process of separating blood components, such as the
interfaces with the pressure sensors, the pumps, the air detectors,
the clamps in particular. The centrifuge chamber may be made of a
rigid plastic. Generally speaking, the term "rigid" used in the
description and the claims to qualify the plastic materials used
relates to materials that are neither flexible, nor soft, nor
pliant, i.e. to plastics capable of preserving their initial shape
in the conditions of use for which they have been designed.
[0003] In the centrifuge assemblies mentioned above, the connection
between the movable part and the fixed part is always made using
flexible tubing which considerably inhibits the mounting of the
centrifuge assembly on the machine, appreciably increasing the
working time of the operator and the risk of defective
mounting.
[0004] It has already been proposed to integrate various elements
of a blood separation device on a rigid support, without all the
same eliminating the flexible tubes between the centrifuge chamber
and the fixed part of the assembly.
[0005] WO 8 402 473 shows a molded structure for a plasma
fractionation machine comprising fluid flow channels and a membrane
filter for separating the plasma from the whole blood. It is not
therefore concerned with separation by centrifugation.
[0006] US 2004/0245189 relates to a single-use separation assembly
comprising a cassette comprising a frame made of injection-molded
plastic that supports tubing ultrasonically welded to the frame and
a continuous flow centrifuge chamber. The centrifuge chamber is
connected in a removable manner to the frame of the cassette in
order to be able to be inserted easily into a rotor of the
centrifuge during installation of the cassette, so that the
centrifuge chamber is uncoupled from the frame of the cassette when
the door of the centrifuge apparatus is closed. The connection
between the fixed connecting tubes for connecting the centrifuge
chamber to the outside and the tubes respectively joined to the
centrifuge chamber is produced using a rotating cylindrical part
having, on its outer face, a series of annular channels, a fixed
part having a face adjacent to the external face of the rotating
cylindrical part is passed through by tubes opening onto this
adjacent face, at respective radial distances from the axis of the
rotating cylindrical part chosen to bring each tube to interact
with an annular channel of the rotating part. The seal between the
rotating cylindrical part and the fixed part is ensured by an
elastic pressure of the adjacent faces of these two parts. Given
the rotation speed of the centrifuge chamber, such a solution poses
serious heating problems which is capable of damaging the processed
blood passing into the annular channels formed on the rotating
cylindrical part, and in the tubes of the fixed part pressed
elastically against the rotating part, rotating at several thousand
rotations/minute to guarantee the seal in the fluid flow.
[0007] The aim of the present invention is to solve these problems
at least partly.
[0008] To this end, the subject of the present invention is a
disposable assembly for separating blood by centrifugation of the
type mentioned above, as claimed in claim 1.
[0009] The appended drawings illustrate, schematically and by way
of example, two embodiments of the disposable assembly for blood
separation which is the subject of the present invention.
[0010] FIG. 1 is a perspective view of a centrifuge machine on
which the disposable assembly is mounted;
[0011] FIG. 2 is perspective view of the disposable assembly
alone;
[0012] FIG. 3 is an exploded perspective view of the disposable
assembly of FIG. 2;
[0013] FIG. 4 is a sectional view along IV-IV of FIG. 2;
[0014] FIG. 5 is a sectional view along V-V of FIG. 6;
[0015] FIG. 6 is a sectional view along VI-VI of FIG. 4;
[0016] FIG. 7 is a detailed sectional view along VII-VII of FIG.
1;
[0017] FIG. 8 is a side elevation view, partly sectional, of a
second embodiment of the invention; and
[0018] FIG. 9 is a variant of FIG. 4.
[0019] The disposable assembly for separating blood or the washing
of a blood component by centrifugation is illustrated by FIG. 2. It
comprises a centrifuge chamber 1 having the form of an elongate
cylinder partly housed in a semicylindrical case 2 joined to a
support 3 in which a network of channels 4 is formed. This support
3 is preferably a generally planar support, only the network of
channels 4 forming a relief relative to this plane. All these
elements are made of a rigid plastic, preferably by injection. The
channels 4 are open laterally onto a face of the planar support 3,
a flexible membrane 6 being fixed by welding or by bonding to the
face of the planar support onto which the channels 4 open, so that
these channels 4 then form tubes that are open only at their two
ends. This membrane 6 is made of a flexible plastic such as
silicone, PUR, PVC plus plasticizer, EPDM.
[0020] The centrifuge chamber 1 comprises an element coupling the
coaxial to its axis of rotation and projecting at its lower end,
through an opening formed in the base of the semicylindrical case
2. This coupling element 1a has inside a housing of noncircular
shape to mesh with a drive member (not shown) of complementary
shape of the centrifuge machine M, illustrated in FIG. 1. The
coupling of the centrifuge chamber with the drive member of the
centrifuge machine corresponds to that of a screw head, preferably
a screw head of the type intended to mesh with an electrical
screwdriver, a large variety of which exist. Other drive systems
are also conceivable. The opposite end of the centrifuge chamber 1
has a tubular opening 1b, concentric with the axis of rotation of
the chamber, in order to receive a member 5 causing this chamber 1
to interact with the outside. A rotary joint is provided at the
tubular opening 1b. This joint may be material or dynamic and
serves to isolate the centrifuge chamber from any outside
contamination. A dynamic joint is understood to be any device
without a material joint capable of forming a sterile barrier
opposing the entry of air into the centrifuge chamber, for example
by creating a slight excess pressure in the chamber, thus causing
leakage of gas exiting this chamber, therefore preventing the entry
of outside air.
[0021] The member 5 causing the centrifuge chamber 1 to interact
with the outside comprises an internal part for supplying the
chamber 1 with blood to be centrifuged and for draining the
separate components thereof. Given that the mode of separation used
by the centrifuge chamber 1 does not form part of the invention and
is not necessary for its understanding, it suffices to specify that
the interaction member 5 comprises a central tube 5a for bringing
blood into the chamber and at least two peripheral tubes 5b, 5c for
draining the separated components, in particular the plasma and the
erythrocytes.
[0022] As can be seen in FIGS. 4 and 5, the outer ends of the tubes
5a, 5b, 5c are stepped and are housed in three respective seats 3a,
3b, 3c of complementary shapes, formed in the planar support 3 and
against which the respective adjacent surfaces of the tubes 5a, 5b,
5c and of the seats 3a, 3b, 3c are fixed to each other, preferably
by ultrasonic welding. Each of the seats 3a, 3b, 3c causes the
tubes 5a, 5b, 5c to interact with one of the channels 4a, 4b, 4c of
the network of channels 4 formed in the planar support 3.
[0023] Due to the fact that both the case 2 and the planar support
3, which advantageously form a single piece obtained by injection,
and the member 5 causing the centrifuge chamber to interact are
made of a hard plastic, when this centrifugation assembly is
assembled after fixing the outside ends of the tubes 5a, 5b, 5c of
the member 5 into the respective seats 3a, 3b, 3c of the planar
support 3, this centrifugation assembly forms a non-deformable
whole that can therefore be mounted very easily with one hand onto
the centrifuge machine M. The open ends of the tubes, formed by the
channels 4a, 4b, 4c laterally closed by the membrane 6 are
connected beforehand to flexible pouches P1, P2, P3, respectively
containing the blood and at least the plasma and the erythrocytes,
and therefore not requiring any mounting.
[0024] The flexible membrane 6 serves to laterally close the
channels 4a, 4b, 4c and at the same time, as illustrated by FIG. 7,
it allows the plungers 7 of the centrifuge machine to deform this
membrane 6 at determined locations. These plungers 7 enable the
opening and closing of the channels 4a, 4b, 4c to be controlled,
thus serving as clamps for controlling the flow into the various
tubes by deforming the membrane 6 into a cavity 8 formed along the
channels 4a, 4b, 4c. Another plunger also makes it possible to
control pumping operations for circulating the fluid in the
channels 4a, 4b, 4c by deforming the membrane 6 into a larger
cavity 9, such as that illustrated in FIG. 1. To this end, this
pumping plunger is moved in synchronization with the plungers 7
serving as clamps. The second embodiment illustrated by FIG. 8
essentially differs from the preceding embodiment in that the case
2 is eliminated. The planar support 3 in which the network of
channels 4 is formed by injection of a rigid plastic into a mold.
In this embodiment, as in the preceding embodiment, the three seats
3a, 3b, 3c are again found, into which the respective tubes 5a, 5b,
5c for causing them to interact with the respective channels of the
network of channels 4 formed in the support 3 are fixed, preferably
by ultrasonic welding. Instead of the plane of the planar support 3
being parallel with the axis of rotation of the centrifuge chamber
1, it is inclined relative to this axis of rotation. The angle of
inclination is given by the inclination of the upper surface of the
centrifuge machine. It is also possible to imagine that this upper
surface is horizontal and that the support 3 is then perpendicular
to the axis of rotation of the centrifugation rotor.
[0025] In this variant, the case 2 which was joined to the support
3 is replaced by a housing 10 of the centrifuge machine M, the base
of which has an opening 10a for allowing through a drive shaft 11a
of a drive motor 11, the end of which meshes with the coupling
element 1a of the centrifuge chamber 1. As in the preceding
embodiment, the channels 4 are laterally closed by a flexible
membrane 6. It is also possible to imagine replacing the case 2 of
the first embodiment with one wall of the machine M.
[0026] This variant without the case 2 of the preceding embodiment
makes it possible to reduce the price of the disposable part. The
housing 10 of the centrifuge machine M in which the centrifuge
chamber 1 is housed also makes it possible to provide better safety
than the case 2 of the disposable assembly of the preceding
embodiment.
[0027] FIG. 9 illustrates a variant in which the seats 3'a, 3'b and
3'c of the support 3' for fixing the tubes 5a, 5b, 5c are no longer
semicylindrical, as in the example of FIG. 4, but are formed by
cylindrical parts that hence completely surround the ends of the
tubes 5a, 5b, 5c enabling better fixing.
[0028] By contrast, while the support 3 and the case 2 of FIG. 4
may be produced by hot working a thermoplastic sheet in the cavity
of a mold, the variant of FIG. 9 can only be obtained by an
injection technique and is therefore more expensive.
[0029] The previously described examples relate to the use of the
disposable assembly for the separation of blood, in particular the
continuous separation of blood. The same assembly could equally
well be used for the washing of blood products by
centrifugation.
[0030] It may, for example, be the deglycerolization of packed red
blood cells before their injection into a patient, glycerol being a
compound added to the packed red blood cells to improve their
conservation, without hemolysis, at low temperature.
[0031] It may also be the washing of blood intended for autologous
transfusion. In this case the patient's blood is collected via
drainage tubes or via a suction cannula. Having been roughly
filtered, the red blood cells are concentrated by centrifugation,
then washed by injecting saline solution into the centrifuge
chamber to remove the impurities and to separate them from the
denser packed red blood cells. The washed red blood cells are
finally extracted and collected in a collection pouch before their
reinjection into the patient.
[0032] It is also possible to imagine washing the blood in batches.
To this end, the blood to be treated is injected into the
centrifuge chamber via the central tube 5a. In this case, the
disposable assembly therefore comprises only a single outlet tube
5b through which the least dense fraction of the fluid is
extracted. Next, the centrifuge chamber 1 is stopped to allow the
more dense residual fraction to fall to the base of this chamber.
This residual fraction is then extracted by siphoning through the
supply tube 5a.
[0033] Current blood separation or autologous transfusion systems
use pumps to control the flow rates entering and leaving the
centrifuge chamber. They may be peristaltic pumps, requiring the
presence of flexible tubes on the single-use assembly, or diaphragm
pumps in the case of a semi-rigid assembly, such as described in
the preceding examples.
[0034] It is, however, also possible to cause the fluid to
circulate toward the centrifuge chamber 1 by raising the height of
the supply pouch P1 relative to the centrifuge chamber so as to
create a motor liquid column, as shown in FIG. 1, and by adjusting
the value of the flow rate by means of adjustable throttling using
a plunger 7, as shown by FIG. 7.
[0035] Similarly, the pressure necessary to transfer components
leaving the centrifuge chamber through to the collection pouches
P2, P3 may be obtained by converting the rotational kinetic energy
of the fluids inside the centrifuge chamber into potential energy
of pressure during their extraction. The adjustment of the flow
rate is then also obtained by means of adjustable throttling.
[0036] The use of pumps is therefore not indispensable.
* * * * *